1. Field of the invention
This invention is generally concerned with the art of road and highway marking with strip or tape material, namely for providing a road or highway with centre-lines or with traffic lane-dividing lines or the like, prevailingly but not exclusively arranged lengthwise of the road.
More particularly, the present invention is concerned with the art of providing traffic signs of the above type, consisting of prefabricated tape material laid on the road surface upon a relatively thin underlayer generally comprising bitumen or asphalt or the like, capable of providing a tape material receiving impervious, flat and planar surface, and securing a firm and permanent bond of the tape material to the road pavement.
Such underlayer is generally and usually indicated, in the art of road surface marking as above, by the word "primer layer" and therefore said expression will be made use of as this description proceeds and in the appended claims.
This invention is principally concerned with the art of compounding, forming, applying on the road pavement and taking advantage of new and advantageous primer composite layer as hereinbelow set forth.
2. Description of the Prior Art
The art of road surface marking with tape material is a well worked one and a wide technical and patent literature thereabout exists. With relation to this art reference is herein made to the U.S. Pat. Nos. 3,399,607 and 3,587,415, of the present Applicant. As far as the machines and devices for providing a road pavement with such markings, reference is also made to the U.S. Pat. Nos. 3,007,838, 3,155,564, 3,235,436, 3,262,375 and 3,844,669, of same Applicant.
It is also known that in relatively recent years the road marking tape materials have been substantially improved by making them "non skidding", that is adapted to provide a sure frictional adherence with the vehicle's tires, such as for example described in the Applicant's U.S. Pat. No. 3,782,842. This provision, which is essential for traffic safety, has made imperative that the tape material shall be most firmly secured to the road pavement to prevent detachement and stripping of the tape off from said pavement, under the extremely severe inertial force exerted by fast and heavy vehicles such as in the event of an emergency braking, accelerations and so on.
It is further known to those skilled in the art that the entire cycle of operations required for marking a road surface involves a considerable overall time, from the moment at which the primer layer composition is laid in contact with the road pavement to that at which the same composition has been hardened and a stable and load and stress resistant layer has been formed.
Further, the presence of moisture or water content on and into the generally porous road pavement increases such time, prejudices the firm primer layer to road pavement bond and leads to serious additional problems.
It is therefore the principal object of the invention to provide a new and advantageous method for road surface marking, comprising the essential steps of forming a primer layer on preliminarily prepared pavement and laying a prefabricated marking forming tape material, the invention including solving the sharply antithetical problems of (i) to shorten as more as possible such overall time and therefore the traffic disturbance and (ii) providing the most firm and permanent binding of the tape material to the road pavement by means of a completely set and properly hardened primer layer which is intimately secured to said prepared pavement.